The present invention relates to devices and methods of the type mentioned in the preambles of the independent claims for performing analyses substantially in parallel.
Mass spectrometers are instruments that produce ions from one or more sample substances, sort these ions based on their mass-to-charge ratios and then record the relative abundance of each species of ion present in a spectrum. These tasks are performed on the samples in sequence. An example of mass spectrometry using xe2x80x9cMALDIxe2x80x9d (matrix-assisted laser desorption/ionisation) is described in U.S. Pat. No. 5,770,860. In this document it is described how thousands of samples can be loaded as spots onto sample supports which are then introduced into the ion source of a mass spectrometer for analysis. The analysis of each spot takes about 2 seconds.
If a sample such as a piece of tissue is cut into thin sections, then it can be attached to a MALDI sample slide. This sample can be thought of as a grid of points (or pixels, if the points will be used to make an image) to be analysed. For example, it may be desired to analyse a grid of 200xc3x97200 pixels (i.e. 40 000 samples). With the prior art methods and devices, it will take 80 000 seconds (over 22 hours) to perform the mass spectrometry analysis. Once the samples have been analysed then data processing of the 40 000 samples also requires a lot of computer memory and processing time. For example, with a spectrum length of 32 000 sample points and a 16-bit intensity scale, more than 2 Gigabytes of memory will be needed to store a single 200xc3x97200 pixel picture. Performing data analysis on this picture, e.g. using peak detection algorithms to form an image of where the mass-to-charge ratio is e.g. 889.3, using prior art devices would require a large amount of disc space and hours of analysis time.
The present invention aims to reduce the time needed to analyse a plurality of samples. According to the present invention, this is achieved by means of a device having the features presented in the characterising part of claim 1 or by means of a method having the features mentioned in the characterising part of independent claim 7.
The invention will now be described in more detail by means of non-limiting examples of embodiments in the following figure and description.